Some modified Autavias are really nice, and considering this, think with me for a minute:
Points to cosider:
0-the watch keeps good time and works properly,(chrono hands reset to zero, etc...),
1-the watch is really useful, bezel scale, etc,
2-the watch looks good,
3-the change was done nicely,
4-looks better than the original,
5-everyone is going to ask where did you get it(if the person doesn't know you can say is a special model only 10 were made),
6-if Mr.Hans put together one I would you buy it? (example of someone you can trust to put one together).
All this considerations and some not so clear take me to conclude:
In the end all watches are put together, sometimes the head of design team tells you; you have to design a dial for a set of hands that they have in stock and they want to use, or use some parts they have in stock for a new watch, and on, and on.
A lot of times the design team has to give up to manufacturing(because they can not make the new design with the resources that they have)or the CEO's want to use they stock of parts(they do not want to invest money.

Best regards,
Marcos